ComplexColorCompat.java
/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.core.content.res;
import static android.graphics.Color.TRANSPARENT;
import static androidx.annotation.RestrictTo.Scope.LIBRARY_GROUP_PREFIX;
import android.annotation.SuppressLint;
import android.content.res.ColorStateList;
import android.content.res.Resources;
import android.graphics.Shader;
import android.util.AttributeSet;
import android.util.Log;
import android.util.Xml;
import androidx.annotation.ColorInt;
import androidx.annotation.ColorRes;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RestrictTo;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import java.io.IOException;
/**
* Represents a color which is one of either:
*
* <ol>
* <li>A Gradient; as represented by a {@link Shader}.</li>
* <li>A {@link ColorStateList}</li>
* <li>A simple color represented by an {@code int}</li>
* </ol>
*
* @hide
*/
@RestrictTo(LIBRARY_GROUP_PREFIX)
public final class ComplexColorCompat {
private static final String LOG_TAG = "ComplexColorCompat";
private final Shader mShader;
private final ColorStateList mColorStateList;
private int mColor; // mutable for animation/state changes
private ComplexColorCompat(Shader shader, ColorStateList colorStateList, @ColorInt int color) {
mShader = shader;
mColorStateList = colorStateList;
mColor = color;
}
static ComplexColorCompat from(@NonNull Shader shader) {
return new ComplexColorCompat(shader, null, TRANSPARENT);
}
static ComplexColorCompat from(@NonNull ColorStateList colorStateList) {
return new ComplexColorCompat(null, colorStateList, colorStateList.getDefaultColor());
}
static ComplexColorCompat from(@ColorInt int color) {
return new ComplexColorCompat(null, null, color);
}
@Nullable
public Shader getShader() {
return mShader;
}
@ColorInt
public int getColor() {
return mColor;
}
public void setColor(@ColorInt int color) {
mColor = color;
}
public boolean isGradient() {
return mShader != null;
}
public boolean isStateful() {
return mShader == null && mColorStateList != null && mColorStateList.isStateful();
}
/**
* @return {@code true} if the given state causes this color to change, otherwise
* {@code false}. If the color has changed, it can be retrieved via {@link #getColor}.
* @see #isStateful()
* @see #getColor()
*/
public boolean onStateChanged(int[] stateSet) {
boolean changed = false;
if (isStateful()) {
final int colorForState = mColorStateList.getColorForState(stateSet,
mColorStateList.getDefaultColor());
if (colorForState != mColor) {
changed = true;
mColor = colorForState;
}
}
return changed;
}
/**
* @return {@code true} if the this color will draw.
*/
public boolean willDraw() {
return isGradient() || mColor != TRANSPARENT;
}
/**
* Creates a ComplexColorCompat from an XML document using given a set of
* {@link Resources} and a {@link Resources.Theme}.
*
* @param resources Resources against which the ComplexColorCompat should be inflated.
* @param resId the resource identifier of the ColorStateList of GradientColor to retrieve.
* @param theme Optional theme to apply to the color, may be {@code null}.
* @return A new color.
*/
@Nullable
public static ComplexColorCompat inflate(@NonNull Resources resources, @ColorRes int resId,
@Nullable Resources.Theme theme) {
try {
return createFromXml(resources, resId, theme);
} catch (Exception e) {
Log.e(LOG_TAG, "Failed to inflate ComplexColor.", e);
}
return null;
}
@NonNull
private static ComplexColorCompat createFromXml(@NonNull Resources resources,
@ColorRes int resId, @Nullable Resources.Theme theme)
throws IOException, XmlPullParserException {
@SuppressLint("ResourceType")
XmlPullParser parser = resources.getXml(resId);
final AttributeSet attrs = Xml.asAttributeSet(parser);
int type;
while ((type = parser.next()) != XmlPullParser.START_TAG
&& type != XmlPullParser.END_DOCUMENT) {
// Empty loop
}
if (type != XmlPullParser.START_TAG) {
throw new XmlPullParserException("No start tag found");
}
final String name = parser.getName();
switch (name) {
case "selector":
return ComplexColorCompat.from(ColorStateListInflaterCompat.createFromXmlInner(
resources, parser, attrs, theme));
case "gradient":
return ComplexColorCompat.from(GradientColorInflaterCompat.createFromXmlInner(
resources, parser, attrs, theme));
default:
throw new XmlPullParserException(parser.getPositionDescription()
+ ": unsupported complex color tag " + name);
}
}
}